


Same Notes, Different Tune

by misfitwolves



Category: Teen Wolf (TV)
Genre: Allison went to France, Alternate Universe - The Little Mermaid, Angst with a Happy Ending, F/M, Fluff and Angst, Peter Hale being creepy, Siren Lydia Martin, mermaid au, siren au
Language: English
Status: Completed
Published: 2014-06-22
Updated: 2014-06-22
Packaged: 2018-02-05 17:27:07
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,838
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1826284
Author URL: https://archiveofourown.org/users/misfitwolves/pseuds/misfitwolves
Summary: <blockquote class="userstuff">
              <p>When Peter forces Lydia to drink a strange concoction she changes from a banshee to a siren, with some dire consequences.</p>
            </blockquote>





	Same Notes, Different Tune

**Author's Note:**

> Summary is horrendous, but it's inspired by The Little Mermaid (the original story not the disney one), Lydia's tail is inspired by Pirates of the Caribbean: On Stranger Tides, and the plot was stuck in my head for an entire week so it's no shock that this is probably the longest thing I've written so far, so read and enjoy!

They arrive just as Peter forces the mixture down Lydia’s throat; it makes her feel strange, as though it hard to breathe and her legs are burning. Her vision is blurry and unfocused, so she hears Stiles’ voice, thick with anger,

“What did you do to her?”

Peter laughs in response and gives, “Same notes, different tune.” As an answer, before he disappears into the night, and though Scott, Kira and Derek all chase after him, he’s too quick and cunning to catch.

Whatever concoction Peter’s given her leaves Lydia unconscious for a few days, and when she does wake up she’s…different. The changes are subtle at first: her red hair shines brighter, without the help of expensive products, her green eyes seem to glow enticingly, her hips swing a little more dangerously when she walks. After a few more days the changes begin to delve into the strange: her voice seems to be able to persuade people to do her every bidding, boys flock to her with a single hair flick (even more than they did before), and despite this Lydia sticks close to Stiles, and she becomes obsessed with water. At first she’s never seen without a bottle of water in hand, then she always has her fingers in a cup of the liquid, until finally she’s always disappearing to the school pool. Stiles, of course, notices these changes first, but pays them no mind until Coach pulls him and Scott out of their free period,

“Can you please get your friend out of the pool, I don’t know what she’s doing but she’s distracting the swim team, Greenburg nearly drowned!”

“Never knew you cared Coach.” Stiles jokes, as they follow him down the hallway, “I don’t, I just don’t want to get sued.”

When they get to the pool they spot Lydia sitting on the side, her feet dangling in the water, her mouth moving as though she was singing to herself; her quiet song seeming to draw the swimmers close to her, like she was drawing them to her.

“Scott we need to get her out of here.” Scott frowned at his best friend, “What’s wrong?” Stiles ran a hand through his hair in frustration, ”I think I know what Peter did to her, what he meant by ‘same notes, different tune’,” It had been haunting him for weeks, and the more Stiles thought about it, the more it made sense.

“What? What did he mean?”

Stiles looks at Lydia, at her half-lidded eyes, and the seductive curl of her lips,

“She’s a siren.”

 

They try to go to Deaton first, but Lydia disappears from the back of the jeep before they reach the clinic; when she doesn’t turn up to school for the rest of the week, Stiles starts to worry. Then a few days later he gets a call from her telling him to come to her lake house, the one where she had that party back when they were thirteen, and before he knows what he’s doing, Stiles is in his jeep driving down the winding paths of the Beacon Hills Reserve. When he arrives he hears Lydia’s voice calling to him, calling him to her; her voice is quiet, almost a whisper, and part of him knows that he shouldn’t be able to hear her from this distance but the rest of him doesn’t care as he walks further down the dock, closer to the edge of the water, closer to her. Lydia’s half in the water, her head resting on her arms on the dock; she smiles as Stiles approaches, reaching up to grab his hand as soon as he’s close enough to pull him down closer to her.

 _“Stiles,”_ She whispers, her voice like a song to his ears; her hand travels up his arm and around to the nape of his neck, and she pulls him even closer, their foreheads touching and their noses brushing against each other, her lips a hair's breadth away from his.

 _‘Stiles,”_ She whispers again, her lips barely brushing against his, as she lowers herself down in the water, pulling him with her, and he goes willingly even though some part of him knows that this was dangerous, that a siren Lydia was dangerous. She’s about to pull him into a kiss when suddenly she gasps, breaking whatever spell Stiles was under, as her hand moves from his neck to the dart now sticking out of her own. Stiles frowns at the sight, and turns his head towards the direction it came from to be met with the sight of Scott, Kira and Malia, with a dart gun in her hands. Lydia’s slackening grip draws his attention back to her and the fact that she’s slipping unconscious and the very real possibility that she could drown. Stiles reaches down into the water, and gripping Lydia’s small waist, pulls her out of the water.

“Whoa.”

The sound of Scott’s surprised voice does nothing to distract Stiles from the fact that Lydia has a tail, and the pale pink scales quickly shift back, as though melting, to her porcelain legs once she’s on the dry dock. Stiles pulls off the plaid overshirt he’s wearing and wraps it around Lydia’s small frame, before hooking one arm under her knees, and putting the other around her, lifting her close to him. Walking past the small group assembled behind him, Stiles mutters,

“Come on, we’re taking her to Deaton.”

 

It’s when they’re walking into the clinic that Lydia wakes up from her drug-induced sleep, “Stiles?” He looks down at her, a small smile on his face at the sight of her awake, “Hey Lydia.” She smiles sleepily, as her hand travels up his chest to his cheek, _“Stiles,”_ She sighs, the melodic tone back in her voice, as she leans up, her lips drawing closer to his, before she’s pulled out of his arms by Scott and Deaton. Stiles yells in protest as he is held back by Kira and Malia, and Lydia screams in anger, hissing and baring her now sharpened teeth at the two males pulling her towards the steel bathtub that had once been the place of Scott, Stiles, and Allison’s sacrifices. They drop her gently into the water, and the change is instantaneous: where her legs were now lies a tail of shimmering rose petal scales, curled underneath her, too long for the metal tub she sits in. Lydia still hisses at them, her teeth still at sharpened points,

"This is unlike anything I've ever seen, sirens and banshees must have a common link; same notes, different tune." Deaton mutters to himself as Scott approaches the girl in the tub,

“Lydia, it’s me Scott.” The alpha tries to calm her down, but she shakes her head and lifts herself out of the water till she’s face to face with him,

“I want Stiles.”

There’s an edge to her tone, but none of the silk that accompanies her persuasion. Scott looks to Deaton, who shrugs in response, “Let her see him, just make sure he doesn’t get too close.” Scott nods, and brings Stiles into the room; Lydia calms down considerably at the sight of him, which relives everyone.

 _“Stiles,”_ She sighs, her voice thick with a seductive tone, _“Come here, Stiles,”_ He tries to come closer to Lydia, enchanted by her words, but Scott’s hand on his arm holds him back, “That’s enough, we’re leaving.” Scott pulls Stiles out of the room, out of the clinic and into his jeep, as Lydia screams in protest until Deaton sedates her again.

Stiles wakes up in the middle of the night to the sound of Lydia’s voice,

 _“Stiles,”_ He blinks, trying to push sleep from his mind so he can concentrate on the noise,

_“Come find me Stiles.”_

She sings his name like a song and he follows the sound blindly; he finds her at the school in the swimming pool, half in the water, head resting on her arms just like she was at the lake house. Again she’s smiling that little smile as her voice draws him closer and closer, until her arms are around him, _“Stiles.”_ She sighs his name as she presses her lips to his and pulls him into the water. They’re still kissing under the water, and Stiles realises that he should be struggling to breathe, he should be drowning, but he isn’t. He breaks away from Lydia and finds that he can breathe perfectly fine. Stiles pulls himself back to the surface and Lydia follows, “I can breathe.” Lydia nods smiling, before pulling his lips back to hers, but Stiles breaks away again, but keeps close to her, “But I shouldn't be able to breathe underwater.” Lydia laughs, “Supernatural, remember?” She breathes against his lips, Stiles frowns, “So you weren’t trying to kill me?” Lydia shakes her head, “No, you’re my sailor, I’m in love with you.” Stiles opens his mouth to reply but a loud growl cuts in,

“Get away from him.”

Stiles turns to the sound and sees Scott, wolfed out, standing on the side of the pool. Lydia cowers at the noise and curls into him, and on impulse he shields her with his body, “Scott it’s fine she wasn’t trying to kill me, I swear,” Stiles gets out of the pool, lifting Lydia into his arms, and heads to the locker room, telling Scott to follow. He pulls his lacrosse sweatshirt from his locker and bundles Lydia in it; it’s too long and almost looks like it could be a dress on her, but she doesn’t care and remains curled in his side.

“Scott calm down, she wasn’t trying to kill me – ”

“But isn’t that what sirens do?”

“Yeah well apparently this siren’s in love with me.”

Scott frowned, “So what does that mean?” Stiles shrugged, “Means that I’m going to have to do more research.”

 

It’s not that Scott doesn’t trust Lydia, it’s just that he doesn’t trust a Lydia that may be under Peter’s control, and after coming so close to losing both Allison and Stiles to the Nogitsune, he doesn’t want to take any chances.

“We need to keep Stiles away from Lydia, at least until we find out what’s going on and what Peter’s plan was.”

“I’ll help keep him away from her.” It’s Malia’s voice he hears first, “I’ll say I need his help with controlling my…abilities.” Scott nods and agrees with the plan, ignoring the part of him that feels as though this is the wrong choice.

Stiles doesn’t see Lydia for two weeks and something is wrong he just knows it; at first it’s the little things that Lydia notices changing: her hair seems duller, her eyes dark and flat, her voice is hoarse at first, until one day it’s gone. Then she starts to find it harder to walk, it hurts to have to hold herself up, her legs burning with every step. Then she finds it harder to breathe, she thinks it might have something to do with being separated from Stiles, but she keeps her thoughts to herself, then she finds her heart hurting, and when she sees Malia kissing Stiles in the hallway, it breaks; and so does she.

Before Stiles knows what is happening, Malia’s lips are on his; he pulls away once the initial shock has passed, “What are you doing?” Malia frowns, “I was, uh – ” Stiles backs away a little and smiles apologetically, “I’m sorry but I’m in love with someone else – ” He stops and frowns as he sees Lydia stumble in the other direction down the hallway, and when she crumples to the ground, he bolts towards her,

“Lydia!”

She lies, unresponsive; her hair fanned around her, her skin pale and ice cold to the touch,

“Lydia? Can you hear me?” His fingers find her weak pulse, and he lifts her in his arms, clutching her close to his chest. “What’s going on?” He hears Scott ask, “I don’t know but we’ve got to get her home, call Deaton, he might know what to do.” Stiles drives his jeep as fast as legally possible, if not faster, to Lydia’s house, and uses the spare keys she gave him (for emergencies only), and rushes to her en suite, gently placing her in the large bath of warm water he’s so glad he’d got Kira to prepare. Lydia’s white dress billows around her in the water, as does the plaid shirt that he’s noticed is his that she wears, her tail lies flat in the water, unfolded, each scale shimmering in the soft light of the bathroom. Stiles stays with her, holding her hand and stroking her hair, until Scott and Deaton arrive.

“I thought it would be safer to keep them apart –”

“What?” Stiles yells in anger, “It nearly killed her!” Deaton frowns at the boy’s outburst, but nods, “Yes from what I’ve seen and read, it does appear that separating a siren from the one she loves can have deadly effects, even worse if it appears that the one she loves, loves another.”

“Me and Malia,” Stiles murmurs in realisation, Scott frowns, “What?”

“She must have seen Malia kiss me, that’s what’s caused this.”

“I’m sorry Stiles, this is all my fault, I shouldn’t have told her to keep you away from Lydia – ”

“No you shouldn’t have.” Stiles sits on the edge of the bed, eyes trained on the bathroom door, a hand running through his hair in anger and frustration at the situation. Scott sits down next to him, “It’s just – after everything with the Nogitsune, I couldn’t lose you, you’re my brother.” When Stiles doesn’t say anything, Scott sighs and carries on, “Lydia’s been controlled by Peter before, she’s dangerous – ”

“That shitstorm happened because we weren’t there to help her, we weren’t there to protect her,” Stiles pauses, before taking a deep breath and continuing, “You should be protecting her Scott, trust me to keep myself safe, I have so far.” He stands and walks away, pulling the bathroom door shut behind him.

Stiles has been sitting beside her for hours before Lydia stirs, she blinks up at him,

“Stiles?” He smiles and nods, before she pulls him down into a kiss, “You’re here,” She breathes against his lips between kisses, “I’m here, I’m not going anywhere, I’m not leaving you, okay? I love you.” She wraps her arms around him as he lifts her from the bath, her tail melting away to reveal her legs, and places her in the bed, then climbing in himself. She curls into him instantly, one hand at the nape of his neck, the other on his heart as he fires off a quick text to his dad saying that he was safe and that he wouldn’t be home tonight, then he wraps an arm around her. They’re silent for a moment before he asks, “So what does this mean?”

She sighs into his shirt, “I don’t know. A 5.0 GPA, a ridiculous amount of knowledge about mythical creatures and I don’t know what’s happening to me, I’ve never read anything about a siren in love – ” She breaks off and buries herself into his chest, “Just as I was getting the hang of being a banshee, now I feel so useless and dependent again.” She feels Stiles shake his head, as he strokes her hair, “You’re not useless, okay? We’ll figure this out together, and you are still the same independent, beautiful, genius Lydia Martin that I know and love.” He feels her face shift into a smile as she nods against him, they’re quiet again before she whispers, “The Little Mermaid.” Stiles frowns, “Huh?” trying to make sure that he’s heard her right, “I said that I’d never read about a siren being in love, but I have: The Little Mermaid, I’m talking about the original not the Disney one.” He nods, “She died didn’t she? When the guy she loved married someone else?”

“She threw herself into the sea, knowing that she would dissolve into sea foam and cease to exist because she couldn’t bring herself to kill him,” She pauses, “I thought I was going to die, when I saw you and Malia I just – ”

“It’s fine, you’re fine, everything’s going to be okay.”

“But what about Peter, what if he controls me again?”

Stiles sighs and drifts a hand through her now dry hair, “Then I’ll protect you, we’ll all protect you.”

Every night following is pretty much the same. Scott checks on them one night, still on edge about Lydia, but when he sees the two of them lying peacefully, the protective way in which Stiles is curled around the petite redheaded siren, causes all doubt to disappear.

“I say we beat him at his own game.” Lydia stands near the head of the table at the Pack Meeting, everyone’s eyes on her; now that it’s been established that she and Stiles can’t be separated, Lydia’s pretty much back to her normal self, “ I’ll lure him to the lake and drown him, I know he wants to see me, I can tell. “ A shiver passes down her spine before she can stop it. “That’s a good idea, he must have turned you for a reason, maybe you can get him to reveal his plan as well.” Malia adds, Lydia barely reluctantly nods in agreement, still harbouring some annoyance at the werecoyote’s apparent feelings for Stiles; Scott agrees as well, “So it’s settled, next full moon, Lydia will lure Peter to the lake, the rest of us are there for back up.”

On the night of the full moon, before they’re about to leave, Stiles pulls Lydia to one side, “Please be safe okay?” Lydia sighs, “I promise, trust me, I’ll be fine sailor.” She adds with a wink, Stiles smiles and rolls his eyes, getting into his jeep with her following, and tries to ignore the feeling of unease in his stomach.

_“Peter, I know what you want,”_ Peter grins at the sound of her melodic tone, “You can’t persuade me you know, it won’t work.” Lydia shakes her head but note the fact that he still moves closer towards her, _“No you’re far to clever for that, too clever and cunning, but you want me for my voice, for my power, don’t you? That’s why you changed me into this.”_

“You’re right, with your power I have the world at my finger tips, I can control anyone – ”

 _“Then come here Peter, and I’ll give you everything you want.”_ The words she’s saying repulse her, but they’re the words that Peter wants to hear. He comes nearer and nearer, but stops just short of her, “How do I know you’re not playing me?”

 _“I’m not, I promise.”_ She urges, but Peter remains unsatisfied, “Prove it, how about we have you kill…” He disappears for a moment but then returns with his hand wrapped around a certain lanky teenage boy’s neck, “…Stiles.” She shakes her head, “No, I can’t.” Her voice breaks in desperation, “I can’t –” rebellious tears are falling from her eyes as Stiles tries to reassure her that it’s okay, that everything’s going to be fine. “Well then, I’ll just have to kill him myself.” Peter’s hand tightens around Stiles throat, and Lydia throws herself at Peter dragging him back into the water with her, holding him under with all her strength. He stills in the water, blood from the scratches she’s given him turning the water red, and just when she thinks he’s dead, Lydia’s pulled under the water and there’s a familiar burning sensation in her arm.

 

Minutes pass after the struggle, and while Stiles can see Peter’s body floating face down in the water, Lydia’s still nowhere to be seen. Hours later, Scott pulls him from the edge of the dock, trying to make him face the possibility that Lydia may have drowned, that she might be dead. A week later, Stiles still can’t accept it and Scott, while he himself is devastated at the loss, has to keep him from going back to the lake house. It’s worse when Allison gets back from France; she marches right up to him and Scott, and after exchanging hellos and bone-crushing hugs, she asks where Lydia is; Stiles has to walk away from the sounds of Allison’s sobs and protests of disbelief as Scott tells her that they think her best friend is dead.

It’s been exactly a month when Stiles finally manages to slip away from Scott and go to the lake house. He’s sitting on the dock, his head in his hands when he senses someone next to him, “Please Scott –”

“Hello sailor.”

His head snaps up at the sound of the voice, at the sound of _her_ voice. “Lydia?” He can’t quite believe what he’s seeing, that he’s seeing her sitting cross-legged next to him, her strawberry blonde hair curling down her back, and her green eyes shining at him. “You’re alive!” He pulls her close, hugging her fiercely, “I was so worried, it was like the winter formal all over again, it was like I couldn’t breathe, why didn’t you come back?” She pulls away looking at him before quickly flicking her eyes down, “Lydia, what’s wrong?”

“I can’t come back.” Stiles frowns, “What? Why?” She looks him in the eye, rolling her lips, a nervous habit of hers he remembers from after she kissed him to stop his panic attack. “When Peter bit me, something changed, now I’m only human every full moon.” She finishes with a bitter smile and a shrug. Stiles takes her hand in his, rubbing his thumb over the back of her hand in comfort, “But what about school, what about college?” Lydia smiles, knowing that he’s really asking about her future, “I’m taking online classes for Stanford, they think I have a rare illness that inhibits me from attending, and with my IQ, GPA, and SAT scores, they’re not really going to question it, so I’ll still get to win my Fields Medal; I think I’m done with playing a nitwit anyway.” He smiles at the fact that she still remembers what he said to convince her to dance with him, he can’t believe that the winter formal was only a year ago; that last year Lydia wouldn’t have even spoken to him, let alone be sitting next to him on her dock holding hands.

“Do – Do you still – ” She breaks off looking down trying to find the right words, “Do you still love me? Or what it just a siren thing,” She trails off, still refusing to look him in the eye. Stiles gently takes her chin in his hand and catches her eye, “It was never a siren thing, I didn’t need any persuasion to love you, I always have.” He kisses her softly, “So I can only see you once a month?” Lydia gives a small scoff, “No you idiot, the rest of the time I’m a mermaid; you can come visit me, Allison does – ”

“Wait, Allison knows?” Stiles thinks back to the past month, and he has to admit that apart from their initial reunion, Allison had seemed extraordinarily unaffected by her friend’s disappearance. Lydia nods, “Yeah, after you guys told her about my ‘drowning’ she came here refusing to believe it, and she found me, she’s been coming every day since.”

“So who else knows?”

“My mom,” Lydia shrugs, tilting her head, “She seem way less freaked out than I thought she would be, she’s already switched out the water in our pool to freshwater, chlorine irritates my tail after a while,” She gives a small laugh, “A year ago who would have thought that I’d be in love with Stiles Stilinski, and discussing my ‘tail’.” Stiles shrugs, “Well to be fair I did have a ten year plan to make you fall in love with me.” She laughs and shoves him; they talk until the sun comes up and Lydia’s legs turn back into her tail, and Stiles reluctantly has to leave because he has school but he promises to visit her every chance he has; he moves with her from the lake house to her pool, school meaning that he's only really able to see her at night; but he doesn't care, he stays with her till the early hours of the morning, her leaning next to him by the side of the pool, her wet hair curling down her back as he watches her tail move gracefully back and forth in the water. Somewhere along the way as the months pass he realises that he really doesn't care that he only really gets to see her at night and that she can only truly be with him for twelve days of the year, he loves her and she loves him, and she's alive, after he's come so close to losing her too many times already, and that's all that matters. 

 

It’s a while after the rest of the pack finds out about Lydia, each with varying reactions: Kira thinks that it's super cool that her friend's still alive and still a mermaid, while Derek still broods over his uncle's actions; that Malia comes on to him again, and when he rejects her, she huffs in frustration,

“I don’t understand, you can only really be with Lydia for twelve days of the year, you can be with me whenever you want!”

Stiles shakes his head, “I’d rather have those twelve days with Lydia than three hundred and sixty five with anyone else.” And with that he walks away from her, and Malia decides to move on.

Every moment that he isn’t at school, with his dad or Scott or Lydia, Stiles tries to find a cure: a way for Lydia to live her life as she used to, he can tell that while she's happy, Lydia misses being able to go places, she misses the freedom her legs gave her. It’s six months later when he thinks he may have found a possible solution in an ancient Greek text that he translates with Deaton’s help; but as he gets closer and closer to perfecting it, the less time he spends with Lydia. When he finally finishes it, he rushes to her house, bursting through the door and heading straight to the pool, where he finds her; half in the water, her head resting on her arms, her tail drifting from side to side, catching the light with each flick. He calls out to her and her eyes widen at the sight of him, “Lydia I need to tell you something.” She looks down, her eyes shiny and stinging with tears, “It’s okay, I understand.” Stiles frowns and walks closer to her, “It’s okay if you don’t want to be with me anymore, I mean I’m half fish for three hundred and fifty three days of the year – ”

“No, Lydia you’ve got it wrong,” He kneels by the edge of the pool, placing one hand on her cheek, “I’ve found a way for you to have legs whenever you want, that’s why I haven’t been able to see you.”

 _“You’ve been looking for a cure?”_ She whispers, her overwhelming emotions triggering the seductive melodic tone to her voice. Stiles nods and pulls a thin chain with a vial of water attached to it, and presents the necklace to her, “A vial of water from the birthplace of sirens, not easy to find, with ancient Greek etched into the glass, which is bulletproof and pretty much indestructible, courtesy of Mr Argent, did you know that the first Sirens were Greek? – ” Lydia ends his rambling by pulling him into a kiss, “Thank you.” She sighs against his lips, before he pulls away to place the necklace around her neck. “Now let’s see if it works.” Stiles reaches down into the water and pulls Lydia out, they’re both silent in the moment it takes before Lydia’s tail wisps away to reveal her legs. She stands, wobbling for a moment, unused to having to support her own weight, before she throws her arms around Stiles, yelling “I have legs!” He laughs and tightens his arms around her waist, lifting her into the air, before remembering her current state of undress, “Urm Lydia? You’re kind of naked right now.”

She looks up at him from under her hooded lashes, a seductive curl to her lip, _“_ _I know, and I don’t care.”_ She giggles at the red blush that covers his entire face within seconds and rolling her eyes grabs a towel from the side to cover herself with. She turns away from him and walks to the patio door before she looks at Stiles from over her shoulder, with an eyebrow raised, _“Well, are you coming?”_ Stiles blinks before he rushes towards her, lifting her giggling form into his arms, running up the stairs to her bedroom; his legs never having moved so fast or so coordinated in his life.    

**Author's Note:**

> So I'm pretty sure they did the do. You can thank you sister for the angst-ridden middle of this fic (I had to put a nice ending), I'm pretty sure she's almost the John Green of fanfic with some of the ideas she comes up with. Please feel free to comment/leave kudos etc. Hope you enjoyed!


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